John Farmer
John Farmer may refer to:
- John Farmer (composer), Renaissance composer of madrigals
- John Farmer (author), American historian and genealogist
- John Farmer (cartographer), Detroit-based mapmaker
- John Farmer (1835–1901), music teacher at Harrow School
- John Stephen Farmer, lexicographer and spiritualist
- John Bretland Farmer, botanist
- John Hind Farmer, SOE Agent, MI6 Agent
- John Farmer (footballer), English footballer who played for Stoke City
- John Farmer Jr., Attorney General, acting governor of New Jersey, and law school dean
- John Q. Farmer, Minnesota politician and jurist